Brook trout

Quick facts

Adult size

30 cm, 500 g typical harvest weight

Days to harvest

365 to 540 days from fingerling

Lifespan (max)

up to 7 years

Diet

carnivore

Temperature class

cold-water

Difficulty

intermediate

Water parameters

Temperature range

2–18°C (optimum 14°C)

pH

6.5 to 8

Hardness

3 to 20 dGH

Minimum tank

300 L per individual at harvest size

Feed and growth

Feed protein

45% target

Daily feed (warm water)

1.20% of body weight per day

Daily feed (cool water)

0.80% of body weight per day

Max stocking density

30 g per litre of system water

A 500g adult eats about 6.0 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 60 g of feed daily.

Legality

Aquaculture and possession rules vary by jurisdiction and change over time. This table reflects regulations as of the verified date on each row. Verify with your local fisheries or wildlife authority before stocking.

Jurisdictions not listed here default to "check local regulations". A non-listing is not a green light; rules in your specific county or municipality may apply.

Habitat and origin

Native to cold freshwater streams, rivers, and lakes across eastern North America, from Georgia and the southern Appalachians north through New England and across eastern Canada. The species (Salvelinus fontinalis) is actually a char, not a true trout, closely related to arctic char and lake trout. Brook trout require the coldest water of any commonly cultured salmonid: optimal temperature is 10–16°C, with stress above 20°C and mortality above 25°C. Wild populations are an indicator species for water quality; they're among the first fish to disappear from degraded streams. The flesh is white to pink with a delicate, sweet flavor. Brook trout are a traditional food and sport fish in Appalachia and New England, with significant cultural importance. Commercially farmed primarily in the northeastern US and Canada.

Climate and outdoor ponds

Climate classification

cold-water (cool water required, dies in heat)

Outdoor pond zones (USDA)

2 to 6 (winter low around -46°C or warmer)

Heating in a temperate climate

Not required (handles seasonal cool periods)

Cooling in a temperate climate

Required if your summer water temperatures exceed the upper tolerance

Zone bounds reflect year-round outdoor pond viability with no active heating. Anywhere outside the bounded zone, the species can still be kept in an indoor heated tank or a seasonally-managed system. Verify your specific microclimate, as a sheltered yard zone can run a half-zone warmer than the regional rating.

Care notes

A cold-water aquaponics species for systems maintaining 10–16°C year-round. Brook trout are more temperature-sensitive than rainbow trout: they stress above 18°C and die above 22–25°C, which limits them to colder climates or well-chilled systems. Growth is moderate: 200–400 g in 12-18 months on salmonid pellet (40-45% protein). FCR is 1.2-1.6, acceptable but slightly less efficient than rainbow trout. Stocking density should be lower than rainbow trout (15-25 g/L) because brook trout are more aggressive and territorial. Males develop hooked jaws (kype) and intensely colored spawning dress in autumn, with bright red-orange bellies and blue-haloed red spots. Dissolved oxygen must stay above 7 mg/L; brook trout are the most oxygen-demanding commonly cultured salmonid. Ammonia tolerance is lower than rainbow trout: keep TAN below 0.5 mg/L. Fingerlings are widely available from state hatcheries and private trout farms across the eastern US and Canada. Legal in most jurisdictions. The flesh commands a premium in local markets, especially in the northeastern US where it's a heritage product. Brook trout are best suited for spring-fed aquaponics systems in Appalachia, New England, or eastern Canada where cold water is naturally available year-round.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else